UNT Theses and Dissertations - 75 Matching Results

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A Characterization of Liver Glyoxalase I From Normal Mice and Mice Bearing Lymphosarcoma

Description: The purpose of this investigation was (1) to isolate and purify glyoxalase I from the livers of normal DBA/lJ mice and the livers from mice bearing a lymphosarcoma tumor; and (2) to determine, at least with respect to glyoxalase I, if the tumor has an effect on the chemical properties or structure of macromolecules in an organ removed from tumor locale and not histologically affected by its presence.
Date: August 1970
Creator: Strzinek, Robert Alfred
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Mixed Culture of Chlorella Pyrenoidosa TX71105 and a Variant Strain of Bacillus Megaterium

Description: Very little work has been done on bacteria capable of significantly inhibiting algal growth. This thesis reports the research on mixed cultures of a high-temperature strain of algae, Chlorella pyrenoidosa TX71105, and an organism isolated from the air and tentatively identified as a variant strain of Bacillus megaterium.
Date: August 1970
Creator: Yao, Raymond Che-Fong
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Some Effects of Electrostatic Fields on Brain Activity in Rats

Description: This study concerned the effects of short-term exposures to continuous (10 kv/meter) and pulsed 20 volts at 640 cps/100 msecs) electrostatic fields on the EEG recorded from external electrodes and hypothalamic activity recorded from implanted electrodes in rats. Each experiment lasted at least 90 minutes. The total energies of the waveforms recorded were integrated and printed out for plotting and analysis. Besides the brain activity, the ECG, respiration, and temperature of the animals were al… more
Date: December 1971
Creator: McCain, Harry B.
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Lipids and Phospholipase Activity of Vibrio Cholerae

Description: One purpose of this investigation is to determine the fatty acid and lipid content of typical Vibrio cholerae cells. The comparison of cholera lipid constituents with those of closely-related bacteria might be of taxonomic value. Furthermore, chemical characterization of the cholera vibrio could provide useful criteria for identification of these disease-producing microorganisms.
Date: August 1972
Creator: Brian, Buford Leo
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Influence of Acclimation and Acclimatization to Seasonal Temperatures on Metabolism and Energetics in the Rusty Lizard Sceloporus Olivaceus

Description: Rates and energy equivalents of consumption (C), egestion+ excretion (FU) , assimilation (A), respiration (R) and production (P) were measured in two groups of Sceloporus olivaceus: 1) a laboratory group acclimated at four seasonally encountered temperatures (15, 20, 25 and 30°C) ; and 2) four acclimatization groups collected at different seasons when ambient temperatures corresponded to 15, 20, 25 and 30°C.
Date: May 1973
Creator: Dutton, Ronald Hugh
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The Vertical Stratification of the Macrobenthos in the Brazos River, Texas

Description: Quantification of stream macrobenthos populations has remained a perplexing problem in rivbrine ecology, despite numerous attempts at improvement. This is in part due to well documented variations in chemical and physical parameters locally and geographically, and resultant adapted macrobenthos populations. Southwood (1968) and Hynes (1970a) have reviewed the various sampling techniques developed'for the census of lotic macrobenthos populations. Needham and Usinger (1956), Chutter (1969), and o… more
Date: December 1973
Creator: Poole, Walton Charles
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Partner: UNT Libraries
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Ecological Energetics of the Dobson Fly, Corydalus Cornutus

Description: Rates and energies of consumption (C), egestion (F), assimilation (A), respiration (R), growth (Pg), production of exuviae (Pev), and production of egg masses (Pr) and associated efficiencies, and the effects of seasonal temperature, weight and metamorphic stage upon these factors were examined for a typical individual and cohort of Corydalus cornutus (L.) from a stream in North-Central Texas (330 23'N, 97*5'W). Dobson flies are apparently univoltine in the study area, with 11 larval instars. E… more
Date: December 1974
Creator: Brown, Arthur V.
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Effects of Shoot X-Irradiation on Water Uptake by Single Isolated Roots of Intact Onion Plants

Description: Using a micro-potometric method, it was ,found that X-irradiation (400 R - 18 Kr) of the shoots of the onion plant Allium cepa will produce an immediate, pronounced (200%) and reversible enhancement of the water uptake by the shielded roots. Unfiltered X-irradiation.(1200 R/min., 120 KVP, 5 ma) was delivered at right angles to the shoot. Readings were taken at 10-minute intervals before, and immediately following X-irradiation. The greatest enhancement occurred at dosages between 4.8 Kr (150%) … more
Date: December 1974
Creator: Chang, Fu-Hsian
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Primary Productivity and Community Metabolism in a Small North Central Texas Pond Ecosystem

Description: Rates of primary production and community metabolism were monitored over a one year period using the diurnal oxygen method. Certain physico-chemical parameters were also measured, and autotrophic standing crops were estimated. An in-depth study was made of the phytoplankton community and various diversity indicies were calculated. Simple correlations were run between all parameters measured (biotic and abiotic), and their inter-relationships examined. Multiple linear regression analyses were us… more
Date: August 1975
Creator: Kelly, Martin H.
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The Effect of Ethanol on Cardiac Activity and Brain Respiration in Chick Embryos

Description: This study concerned the effect of ethanol on cardiac activity and brain respiration in chick embryos. Ethanol dosages tested ranged from 1.0 mg to 4.0 mg/g weight. Each experiment lasted at least 150 minutes. Cardiac activity in terms of total waveform energies was integrated and printed out for plotting and analysis. The embryonic heart rates were simultaneously determined from physical graph tracings. The embryonic brain respiration was measured using a differential microrespirometer. The ef… more
Date: August 1976
Creator: Newman, James J.
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The Effects of Diphenylhydantoin on the Lymphoreticular Tissues of the Rat

Description: A study was made of the effects of diphenylhydantoin (DPH) and the carrier solution on the spleen, lymph node, and thymus. DPH was injected i.p. at concentrations of 5 and 10 mg./100 gm. for 30 and 60 days. Hematologic effects observed were leucocytosis, neutrophilia, eosinophilia, and lymphopenia. Respiratory measurements of lymph node tissue slices were made using the oxygen electrode method. The carrier solution was found to cause a marked increase in oxygen consumption. A DPH effect on lymp… more
Date: August 1976
Creator: Gordon, Charles K.
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Aspects of the Thermal Ecology of Largemouth Bass (Micropterus salmoides) in North Central Texas

Description: The coefficient of body temperature change (K) ranged from -0.53 to -0.072 for bass weighing 73-1440 g. The double log regression of K on weight was similar to that reported for other poikilotherms (slope = -0.57; R = 0.93). Fingerling bass were eurythermal, being capable of surviving instantaneous temperature changes over a 20 C range at acclimation temperatures of 15, 25 and 30 C and over a 15 C range at acclimation temperatures of 20 and 35 C. Preferred temperatures for adult bass measured i… more
Date: December 1976
Creator: Venables, Barney J.
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Serological Relationships of Azotobacter Species

Description: In order to clarify the taxonomic problems which exist among the group azotobacter by serological method, 24 cultures of Azotobacter including 9 species were tested as antigens in Ouchterlony plates against 3 different antisera obtained from rabbits immunized with A. chroococcum ACl6, A. macrocytogenes St.M. and A. vinelandii 12837, respectively. The results showed more cross reactivity in intraspecies reactions than in interspecies ones and indicated the presence of a common immunogenic determ… more
Date: December 1976
Creator: Chang, Chyan-chuu
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Limitation of Primary Productivity in a Southwestern Reservoir Due to Thermal Pollution

Description: Evidence is presented to support the conclusions that (1) North Lake reservoir is less productive, contains lower standing crops of phytoplankton and total organic carbon than other local reservoirs; (2) that neither the phytoplankton nor their instantaneously-determined primary productivity was detrimentally affected by the power plant entrainment and (3) that the effect of the power plant is to cause nutrient limitation of the phytoplankton primary productivity by long-term, subtle, thermally… more
Date: August 1977
Creator: Stuart, Tom J.
Item Type: Refine your search to only Thesis or Dissertation
Location: 32.941831 -96.978633
Partner: UNT Libraries
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The Relation Between Carbon Assimilation and Biomass Dynamics in a Phytoplankton Community

Description: Production dynamics in the phytoplankton community of a mesotrophic Texas reservoir were measured weekly over a four month period using 14C incubation and ATP assay methodologies. Assimilation values of 14C ranged from 0.2 to 45 ug C 1 hr1 - . Significant positive and occasionally negative changes in biomass (i.e. viable organic carbon) were observed in short term (4 hr) in situ incubations juxtapo-sitioned with the 14C experiments; viable organic carbon production, estimated with the ATP assay… more
Date: December 1977
Creator: Wilcox, Douglas P.
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Dielectric Properties of Azotobacter vinelandii in a Microwave Field

Description: A resonant frequency cavity was used to determine the dielectric properties of various preparations of Azotobacter vinelandii ATTC 12837. It was found that the bacteria investigated did interact with microwave radiation in the absence of free water. The data presented here indicate that bacteria demonstrate frequency specific dielectric properties. The techniques employed in these experiments may also be used to determine microwave spectra of other species of bacteria in different physiological… more
Date: December 1978
Creator: Hargett, John M.
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The Life History of the Mayfly Isonychia sicca (Walsh) (Ephemeroptera--Siphlonuridae) in an Intermittent Stream in North Central Texas

Description: The life history of Isonychia sicca (Walsh) was elucidated from samples collected at Clear Creek from Oct. 1976-Jun. 1978, and Elm Fork of the Trinity River from Sept. 1977-Jun. 1978, Denton County, Texas. Adaptations for existence in an intermittent stream were of primary concern. Eggs are capable of diapausing through hot, dry summers and cold, wet or dry winters. Diapause is broken in the fall after rehydration and/or in the spring. I. sicca is usually bivoltine during a Sept.-Jul. wet perio… more
Date: December 1978
Creator: Grant, Peter M., fl. 1978-
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Size Fractionation of Metabolically Active Phytoplankton and Bacteria in Two Diverse Lentic Systems

Description: Simultaneous size fractionation of plankton populations associated with NaH^14CO_3 and ^3H-glucose uptake was employed in eutrophic Lake Texoma (Texas and Oklahoma) and oligotrophic Flathead Lake (Montana). Autoradiography was utilized to determine the role of specific microorganisms in community metabolism. Ultraplankton (0.45-10 μm) dominated plankton numbers and metabolic activity in both aquatic systems. Many of the most abundant species were not the most productive, in terms of inorganic C… more
Date: August 1980
Creator: Ellis, Bonnie K.
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Population Dynamics of Macrobenthos in a Regulated Stream 1970-71 and 1978

Description: Stability of the macrobenthic community in a regulated section of the Brazos River, Texas, was evaluated. Physicochemical data and information on spatial distribution of macrobenthos were collected. Populations of two invertebrate species, Isonychia sicca and Neoperla clymene, had been greatly reduced since 1970-71 and I. sicca had been practically eliminated from this section of the Brazos. Three other insect populations, Choroterpes mexicanus, Cheumatopsche campyla and Cheumatopsyche lasia, h… more
Date: August 1981
Creator: Coulter, James D. (James Duard)
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Chemically Active Odorants as Olfactory Probes

Description: The initial step in odor recognition by the nose is the binding of odorant molecules to receptor sites embedded in the dendritic membranes of olfactory receptor cells. Despite considerable interest and experimentation into the nature of these receptor sites, little is known of their specificity to different types of odorant molecules. This lack of knowledge partially stems from the fact that the nature of receptor proteins is most effectively studied when specific and irreversible inhibitors ar… more
Date: May 1982
Creator: Criswell, Darrell W. (Darrell Wayne)
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Effects of Aging on ACTH-Stimulated Steroidogenesis in Subcellular Fractions from Rat Adrenal Glands

Description: Young, middle-aged and old rat adrenal gland steroidogenesis was measured in isolated, superfused glands and in their subcellular fractions before and after adrenocorticotropic hormone treatment. In the latter experiment, five corticosteroids were extracted from six different subcellular fractions. Superfused glands initially produced relatively high glucocorticoid levels; thereafter, production decayed asymptotically. Steroidogenesis by young and middle-aged glands was maintained at least 1.5 … more
Date: August 1982
Creator: Sawada, Tadao
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Effects of Pulp and Paper Mill Effluent on Stream Primary Productivity in the Lower Sulphur River, Texas

Description: Responses of periphyton and phytoplankton productivity in the lower Sulphur River (Texas-Arkansas) to bleach-kraft mill effluent (BKME) were monitored using in situ ¹⁴C incubation. Carbon assimilation rates measured downstream of mill discharge were substantially reduced from upstream levels. Periphyton and phytoplankton chlorophyll a concentrations remained relatively unchanged by the presence of BKME. Periphyton ash-free dry weight increased near the mill outfall, but decreased further downst… more
Date: August 1982
Creator: Davis, Terrence Marvin
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Comparative Feeding Ecology of Leaf Pack-Inhabiting Systellognathan Stoneflies (Plecoptera) in the Upper Little Missouri River, Arkansas

Description: The feeding ecologies of leaf pack-associated systellognathan stoneflies were examined from 6 June 1980 21 May 1981. Species composition, seasonal abundance, nymphal growth, feeding habits and mouthpart morphology were determined for the eight dominant stonefly species. Prey preferences and predator-prey size relationships were also examined for omnivorous and carnivorous species. Foregut analysis from 2860 individuals indicated opportunistic feeding on the most abundant prey insects, usually i… more
Date: August 1983
Creator: Feminella, Jack W. (Jack William)
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Comparative Ecology of Benthic Communities in Natural and Regulated Areas of the Flathead and Kootenai Rivers, Montana

Description: A comparative study was made of environmental variables and the density, biomass, diversity, and species composition of macroinvertebrates in areas downstream from a dam with a hypolimnetic release (Hungry Horse Dam on the Flathead River) and a dam with a selective withdrawal system (Libby Dam on the Kootenai River). A major objective of this study was to examine the response of macroinvertebrate communities to defined environmental gradients in temperature, flow, substrate, and food-related va… more
Date: May 1984
Creator: Perry, Sue A.
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